“There is no longer any valid basis for the current salt guidelines” that recommend no more than 2,300 milligrams of sodium a day, warns one researcher on a landmark study published last year in the New England Journal of Medicine.

“So why,” she asks, “are we still scaring people about salt?”

OK, the debate’s far from settled. Both sides agree that too much salt in the diet is dangerous. But they have very different ideas about just how much is too much.

Salt guidelines have been in effect for more than three decades, but the advisable target number has shifted over the years.
And even the author of the landmark 1973 study that served as the basis for the dietary guidelines says her paper was meant to spur more research, not serve as final word on the subject.

All of which should remind us that even the most overwhelming scientific consensus — whether on healthy diets or, yes, even climate change — is still a work in progress.

Sometimes the findings hold up. But often they won’t. That’s science.

Federal officials, in particular, need to stop pushing the idea that tentative findings are hard fact. For decades, the feds pushed the Food Pyramid diet — only to eventually realize they’d gotten it almost exactly wrong.

All too often, you just have to take what the scientists say with a large, er, grain of salt.